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Infectious Causes Impacting Reproduction. Fetal Mummification Fetus dies, uterus contracts, and fluid is resorbed  fetus becomes dry/firm –Thickened.

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Presentation on theme: "Infectious Causes Impacting Reproduction. Fetal Mummification Fetus dies, uterus contracts, and fluid is resorbed  fetus becomes dry/firm –Thickened."— Presentation transcript:

1 Infectious Causes Impacting Reproduction

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3 Fetal Mummification Fetus dies, uterus contracts, and fluid is resorbed  fetus becomes dry/firm –Thickened uterus –CL present on ovary –No palpable cotyledons –No membrane slip –No fremitus in uterine artery –Palpable mass in uterus

4 Fetal Mummification Most common at 4-6 months of gestation, but may go beyond gestation length –Genetic (uncommon) – Jerseys, Guernseys, certain Holstein families –Torsion of umbilical cord –Infectious diseases that cause minimal inflammation: Campylobacter fetus BVDV Tx: – PGF2a IM to lyse CL and expel fetus in 2-3 days +/- 2 nd dose in 96 hrs if needed – Manually remove with lube – C-section

5 Fetal Maceration Fetal death with partial cervical dilation  uterine contamination  bacterial growth (great medium!) Any age of gestation CS: abdominal straining, foul fetid vulvar discharge, fever, anorexia, milk production +/- diarrhea Rectal: distended swollen uterus, gas crepetation in fetus Prognosis for future reproduction POOR - treatment not always successful, endometrial damage extensive Tx: –Cervix dilated: fetus removed manually with LUBE and SLOW manipulation. Re-examine for 2 nd fetus! –Cervix closed: PGF2a +/- oxytocin (less successful than with mummies; may not be functional CL)

6 Abortion Severe maternal illness: –Infectious diseases: high fever, inflammation (mastitis, pneumonia, virus…) –Toxins: plants and chemicals (nitrates, moldy sweet clovers, fescue molds, lupines, gossypol in cottonseeds, and industrial pollutants…) –Hypoxia (anemia, pneumonia…) –Endotoxemia Placentitis: –Hematogenous –Ascending via cervix Fetal origin: –Fetal stress → death

7 Abortion Mechanism: – P4 and PGF2a  luteolysis + expulsion of fetus

8 Due to the degree of autolysis and edema of fetuses in utero after death but before expulsion, gross placental/fetal lesions are not usually diagnostically significant. Abortion

9 What tissues samples shall I send off ? –Fetal membranes/aborted fetus – BEST! –Fetal lung, liver, intestines, brain, kidneys… –Maternal serum, urine, vaginal discharge… FRESH, keep cool Better too many than too few samples…

10 Abortion Infectious Causes: Bacterial –Brucella spp –Listeriosis –Leptospirosis –Arcanobacterium pyogenes –Vibriosis Protozoal –Trichomonas –Neospora Viral –IBR –BVD Mycotic *Especially if abortion storm!

11 Brucellosis “Contagious abortion”, “Bangs disease” Brucella abortus ZOONOTIC – Undulent fever in humans (via milk) Eradication program  ~rare in US herds, but still in free-ranging bison/elk Highly infectious – spread via aborted fetus, placenta, vaginal discharge, milk, or semen from infected bull Lesions – chorionic placentitis, Moroccan leather appearance, focal necrosis of cotyledons, thickened intercotyledonary areas with yellow exudate

12 Brucellosis Abortion usually between 5th-8th month of gestation –Also frequently causes retained placenta, weak calves and infertility Dx: serology/culture of fetal abomasal fluid, lung, and liver, placenta, uterine fluid, milk, serum, seminal plasma Prevention/Control: Official calfhood vaccination –RB-51 vaccine (“bangs” vaccine) + Official USDA Brucellosis eartag + official ear tattoo –Calves 4-10 months of age –By state and federal brucellosis program personnel and USDA accredited veterinarians

13 Listeriosis “Circling Disease” Listeria Monocytogenes ZOONOTIC Widespread in environment; transmission via ingestion of poorly fermented silage Fever, weight loss, endometritis, encephalitis Lesions: suppurative placentitis, small white foci on fetal liver and cotyledons, fibrin in fetal body cavity

14 Listeriosis Abortion usually during 3 rd trimester –Sporadic or abortion storm –Retained fetal membranes Control: stop feeding spoiled material, isolate aborting cows –Broad Spectrum Antibiotics  milk withdrawal due to milk residues! –NO vaccine in US

15 Leptospirosis Leptospira interrogans serovars hardjo & pomona Transmission via infected urine, placental fluids, milk, or contaminated environment/water source Abortion from 4 months to term +/- yellow MM, blood tinged urine and milk –Weak calves or infertility is also common Dx: Culture - organisms in fetal kidney Tx: Vaccinate annually

16 Arcanobacterium pyogenes Abortion at any stage of pregnancy Normal inhabitant in nasopharynx of many cows, also in abscesses, NOT in fetuses or fetal membranes = always significant! Bloodstream  endometritis & placentitis (diffuse with a reddish brown to brown color) Fetus: autolyzed, with fibrinous pericarditis, pleuritis, or peritonitis possible, as well as bronchopneumonia Dx: culture from placenta or abomasal contents NO effective bacterin available

17 *Important cause of pyometra post-calving in DAIRY cows! –Diagnosed at pre-breeding check (~ 40 d post calving) –Occurs when cow ovulates in face of A. pyogenes in uterus  pyometra Usually uterine contaminates are expelled from uterus during normal involution process Pre-disposing factors: dystocia, RFM, metritis Arcanobacterium pyogenes

18 Vibriosis Campylobacter fetus subsp venerealis Bulls are asymptomatic carriers, permanent carries when > 4 yrs Venereal transmission  organism attacks conceptus  early embryonic death (occasional abortions ~ 4-7 months of gestation) Cows develop immunity and conceive, and maintain the disease in the herd (carriers) Dx: Blood agar culture of preputial smegma, fetal abomasal contents, vaginal/cervical mucous Tx: ID and cull carriers, topical antibiotic ointment Control/Prevention: AI, prevent re-infection, blood culture all non-virgin bulls 6-8 weeks before breeding season, VACCINATE cows and bulls

19 Trichomoniasis Trichomonas foetus Bulls are asymptomatic permanent carriers Venereal transmission  organism attacks conceptus Cows develop immunity and conceive (carriers) *Important cause of pyometra post-breeding in BEEF cows CS: infertility, pyometra, abortion Dx: microscopic isolation of organism (preputial smegma or vaginal/cervical mucous) with Diamond’s medium (Klaas modification) Control/Prevention: AI, use of virgin bulls –NO vaccine available

20 Neospora Neospora caninum Cycles between canids and ruminants – oral or vertical transmission Mid-gestation abortion (~4-6 months), pre- mature calf, birth of impaired calf, or normal calf Brain hemorrhage, myocarditis

21 Oocysts ingested while grazing  Sporozoites released, enter SI  reticulo-endothelial system  Tachyzoites = invade different tissues, placenta  fetus in pregnant animals  Bradyzoites = dormant, within tissue cysts (found mainly in neural tissue) In future pregnancies, bradyzoites  tachyzoites  invade the fetus via the placenta

22 Infectious Bovine Rhinotracheitis (IBR) Acute, contagious Bovine Herpes Virus Infertility, respiratory infections, conjunctivitis, abortion storm usually > 5 months gestation RFM, placental edema/vasculitis Fetus: red serous body fluid, white foci on liver/lungs Tx: Vaccinate annually “red nose”

23 Infectious Pustular Vulvovaginitis Also a Bovine Herpes Virus Venereal/mechanical spread Genital pustules (balanoposthitis) Spontaneous recovery

24 Bovine Viral Diarrhea Virus (BVD) Affects the digestive, respiratory, immune, nervous and reproductive systems BVD Type I and Type II, each with: –Cytopathic (CPE) strains  cellular vacuolation and cell death –Non-cytopathic (non-CPE) strains  no visible cytopathic change in cell cultures

25 BVD infection in-utero: –Slows fetal growth  lower birth weight, bone growth –Abortion (at any trimester) –Early embryonic death –Stillbirth –Congenital Birth Defects (eye, thymus, brain) –Arthrogryposis –PI Calves (immunotolerant and persistently infected shedders) –Normal calf born with antibodies to the BVD virus Bovine Viral Diarrhea Virus (BVD) cerebellar hypoplasia

26 Bovine Viral Diarrhea Virus (BVD) OutcomeGestational age at time of in utero infection days > 180 days Normal, antibody negative calfXXXX AbortionXXXX Early embryonic death, resorptionX MummificationXX StillbirthXXX Congenital defects, antibody negativeX Congenital defects, antibody positiveX Persistently infected, "normal" calfX+/- Normal, antibody positive calf+/-X Results of fetal infection with BVDV

27 Bovine Viral Diarrhea Virus (BVD) Mucusal disease: –PI calf (infected in-utero from d of gestation with non-CPE strain, seem normal, but have no immunity to the virus) –+ encounters CPE strain after birth (vulnerable to severe effects of the CPE cell- killing strain) –~6 months – 2 yrs old –High mortality

28 BVD infection after birth: –Usually 6 months to 2 yrs of age –CS: vary depending on the virulence of the strain –Viremic  develop antibodies  clear virus within days –Subclinical (estimated 70-90% of BVDV infections) Mild elevation in body temp, drop in milk production –Clinical = Acute BVD Depression, fever, inappetence, nasal discharge, transient leukopenia, thrombocytopenia, petechial hemorrhages, diarrhea, high morbidity, low mortality Eliminate Carriers = CULL! VACCINATE before breeding Bovine Viral Diarrhea Virus (BVD)

29 Mycotic Abortion Aspergillus, Absidia, Mucor, Rhizopus, Candida More in WINTER when cattle housed/fed inside Injury to respiratory/GIT  hematogenous  uterus  severe necrotic placentitis –Thick, leathery cotyledons + intercotyledonary placenta Abortions in 3 rd trimester Head and neck lesions on fetus

30 “ Given the low diagnostic success rate, the high cost of laboratory work, and the low profit margin in both the beef and dairy industries, veterinarians should not attempt to make an etiologic diagnosis in every abortion. Instead, veterinarians should become concerned if fetal loss is >3-5% per year or per month.” ~ The Merck Veterinary Manual


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